|
Basic Characteristics of Mutations
|
|
Mutation Site
|
R292K |
|
Mutation Site Sentence
|
Drug susceptibility profile and pathogenicity of H7N9 influenza virus (Anhui1 lineage) with R292K substitution. |
|
Mutation Level
|
Amino acid level |
|
Mutation Type
|
Nonsynonymous substitution |
|
Gene/Protein/Region
|
NA |
|
Standardized Encoding Gene
|
NA
|
|
Genotype/Subtype
|
H7N9 |
|
Viral Reference
|
-
|
|
Functional Impact and Mechanisms
|
|
Disease
|
Influenza A
|
|
Immune
|
- |
|
Target Gene
|
-
|
|
Clinical and Epidemiological Correlations
|
|
Clinical Information
|
- |
|
Treatment
|
oseltamivir;zanamivir;peramivir |
|
Location
|
China |
|
Literature Information
|
|
PMID
|
26038501
|
|
Title
|
Drug susceptibility profile and pathogenicity of H7N9 influenza virus (Anhui1 lineage) with R292K substitution
|
|
Author
|
Zhang X,Song Z,He J,Yen HL,Li J,Zhu Z,Tian D,Wang W,Xu L,Guan W,Liu Y,Wang S,Shi B,Zhang W,Qin B,Cai J,Wan Y,Xu C,Ren X,Chen H,Liu L,Yang Y,Zhou X,Zhou W,Xu J,Zhang X,Peiris M,Hu Y,Yuan Z
|
|
Journal
|
Emerging microbes & infections
|
|
Journal Info
|
2014 Nov;3(11):e78
|
|
Abstract
|
Neuraminidase inhibitors (NAIs) are the only available licensed therapeutics against human H7N9 influenza virus infections. The emergence of NAI-resistant variants of H7N9viruses with an NA R292K mutation poses a therapeutic challenge. A comprehensive understanding of the susceptibility of these viruses to clinically available NAIs, non-NAIs and their combinations is crucial for effective treatment. In this study, by using limited serial passage and plaque purification, an R292K variant of the Anhui1 lineage was isolated from a patient with clinical evidence of resistance to oseltamivir. In vitro and cell-based assays confirmed a high level of resistance conferred by the R292K mutation to oseltamivir carboxylate and a moderate level of resistance to zanamivir and peramivir. Non-NAI antivirals, such as T-705, ribavirin and NT-300, efficiently inhibited both the variant and the wild-type in cell-based assays. A combination of NAIs and non-NAIs did not exhibit a marked synergistic effect against the R292K variant. However, the combination of two non-NAIs (T-705 and ribavirin) exhibited significant synergism against the mutant virus. In experimentally infected mice, the variant showed delayed onset of symptoms, a reduced viral load and attenuated lethality compared with the wild-type. Our study suggested non-NAIs should be tested clinically for H7N9 patients with a sustained high viral load. Possible drug combination regimens, such as T-705 plus ribavirin, should be further tested in animal models. The pathogenicity and transmissibility of the R292K H7N9 variant should be further assessed with genetically well-characterized pairs of viruses and, most-desirably, with competitive fitness experiments.
|
|
Sequence Data
|
-
|
|
|